Typewriter printing means for symbols in coded inks

ABSTRACT

Symbols in coded inks in which the code in the presence or absence of photoluminescent constituents is effected on a modified teletypewriter mechanism by clipping onto the back of a standard teletypewriter type head a portion of ribbon with separate areas registering with the type heads, each area being impregnated with a coded ink having the proper presence or absence of coded photoluminescent components corresponding to the symbol of the type head. The areas are separated from each other somewhat, as is always the case with the teletypewriter head, and so contamination of the coded ink impregnated in one area with that in another area cannot take place. The teletypewriter head is provided with a clip frame and the inked ribbon portions are in suitable disposable frames which slide into the clip and are self-registering.

United States Patent lnventor Robert 11. Postal Clifton, NJ.

Appl. No. 856,959

Filed Sept. 11, 1969 Patented May 11, 1971 Assignee American CyanamidCompany Stamford, Conn.

TYPEWRITER PRINTING MEANS FOR SYMBOLS 1N CODED INKS 3,481,446 12/1969Burkhardt etal Primary Examiner-Robert E. Pulfrey AssistantExaminerStephen C. Pellegrino Attorney-Samuel Branch Walker ABSTRACT:Symbols in coded inks in which the code in the presence or absence ofphotoluminescent constituents is effected on a modified teletypewritermechanism by clipping onto the back of a standard teletypewriter typehead a portion of ribbon with separate areas registering with the typeheads, each area being impregnated with a coded ink having the properpresence or absence of coded photoluminescent components correspondingto the symbol of the type head. The areas are separated from each othersomewhat, as is always the case with the teletypewriter head, and socontamination of the coded ink impregnated in one area with that inanother area cannot take place. The teletypewriter head is provided witha clip frame and the inked ribbon portions are in suitable disposableframes which slide into the clip and are self-registering.

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' ,sumaorz j U hu'uuununuu INVENTOR. ROBERT H. POSTAL A T7 ORA/E YTYPEWRITER PRINTING MEANS FOR SYMBOLS IN CODED INKS RELATED APPLICATIONSAND BACKGROUND OF THE INVENTION Coded inks and coding of symbols, suchas alpha numeric symbols, has been described and claimed in a number ofapplications assigned to the assignee of the present invention. In theFreeman and Halverson application Ser. No. 596,366, filed Oct. 14, 1966,and now U.S. Pat. No. 3,473,027, which application is acontinuation-in-part of application Ser. No. 437,866, filed Mar. 8,I965, and now abandoned, there is described a coding procedure andcoding inks in which various symbols are represented by the absence orpresence in at least one concentration of photoluminescentcodingcomponents, for example narrow band luminescers such as thosecontaining lanthanide ions with an atomic weight greater than 57. Anumber of applications, assigned to the assignee of the presentinvention, have been filed for means for printing the symbols, forexample the prior application of Postal, Ser. No. 560,321, filed June24, 1966, which describesa modified typewriter with stylized typeface onlines of different photolurninescent components, the typeface opaqueingcertain portions of the lines with the typed stylized symbols. Thisapplication and others have required rather special material or specialmodifications of typewriters or other devices.

The number of symbols whichcan be represented by presence or absence ofcomponents is 2' -l in which n is the number of coding components, or inthe case of presence in two different concentrations, 3"l. The.photoluminescing components are, in general, uncolored, and therefore,symbols can be represented which are secret and are only readable byillumination with ultraviolet light. It is also possible to have thesymbols readable visually by incorporating in the inks a suitablepigment or coloring matter which can be seen under ordinary light.

One of the problems which arises in contamination of one coded ink byanother. Where the photoluminescentefficiency of the photoluminescers ishigh, that is to say the amount of luminescing color for a givenintensity of ultraviolet illumination, the problem is of little or noimportance because contamination can be completely swamped. However,unfortunately, some of the best narrow-band fluorescers have onlylimited efficiency and so contamination of the inks in one symbol withthose from another symbol can lead to spurious responses. I

SUMMARY OF THE INVENTION a box with each type having its own spring-heldactuating rod.

For each symbol on striking the proper key in the teletypewriter the boxis positioned so that a particular typehead is opposite the typingposition, a stationary platen, that is to say a platen which while itcan turn does not move from right to left. The same mechanism whichpositions the type with respect to the platen also positions it withrespect to a striking hammer, which is usually electrically operated andwhich is opposite the typing position. When a key is struck, the boxmoves to the proper position and then the hammer is actuated so that theparticular type strikes through a conventional n'bbon onto the paper.After each symbol is typed, the box moves one space to the right, sothat when it is aligned for a symbol in this position by striking oneof'the keys the symbol is printing to the right, and so on until a lineis filled, at which-time the box is electrically returned to theleft-hand margin and the platen is turned one line. Usually ateletypewriter operates with paper in the form of a continuous ribbonwhich is torn off when a message is completed, although this is notnecessary and separate sheets may be used.

In an ordinary teletypewriter the ribbon is, of course, of a singlecolor, as is the case with most ordinary typewriters, and the message isprinted with the symbols readable visually, as in ordinary typewriting.Some simplified teletypewriters do not use upper and lower case and allletters are printed in capitals, but, as will be seen, from thestandpoint of the present invention this is immaterial.

In the present invention the teletypewriter typing box is only slightlymodified by clipping or otherwise removably attaching to its back aholder with a slot in which a frame carrying a piece of ribbon can beinserted. The holder is provided with guiding means so that a ribbonframe or portion of ribbon cannot be inserted in the wrong alignment. Ofcourse the ordinary typewriter ribbon for the teletypewriter is removed.The typewriter ribbon in the frame is of a very special kind. It hasareas aligning with'each typeface on the teletypewriter typing head orbox andeach area is impregnated with a different coded ink thephotoluminescent coding components of which correspond to the symbol onthe type head. As the type heads on the ordinary teletypewriter box aresomewhat separated, so

are the areas on theribbon, and contamination of one area with the otheris, therefore, impossible, so that the problems due to codingcontamination are completely eliminated; The typewriter ribbon ismounted in a suitable'fra'me, which may be disposable, such ascardboard, or reusable, such as metal, and which holds theribbon rigidlyso that the alignment with the various type heads cannot be disturbed.The frame usually also is'provided with a suitable tab which canbegraspedby the fingers for replacement of the ribbon when impressionsbecome too light. The ribbon frame fits in the holder so that there isaslight amount of play, permitting type faces to strike slightlydifferent portions of each inked ribbon area to increase the number ofimpressions before a new frame or new portion of ribbon is inserted. Theplay should be sufficiently slight so that under no circumstances willmisalignments of inked areas take place.

'Iltecoding components are, of course, photoluminescent, and, as isdescribed in the Freeman and Halverson patent referred to above, it isdesirable to use for at least some of the components narrow-bandfluorescers containing lanthanide ions of atomic'number greater than 57.It is also possible to have a broader-band fluorescer but normally onlyone such should be used. The particular lanthanide ions are not changedby the'present invention nor in fact is any photoluminescent componentso changed. This is an advantage of the present invention as it does notrequire the development of any new or different photoluminescentcomponents. A large number of ribbons can be impregnated throughsuitable masks as, of course, the frames with the ribbons in have to bechanged more often than an ordinary typewriter ribbon because theycannot move to expose fresh impregnated areas. However, the insertion ofa frame with a new piece of ribbon is so simple and so quick that thisdoes not constitute a significant problem.

Where the number of components which photoluminesce may be somewhatlimited, as is often the case, it is possible'to provide for a muchlarger number of coded symbols by also including some components whichselectively reflect in the vi'sible. However, it is usually preferablewhere possible to use coded inks in whichall of the coding componentsare photoluminescent. As is described in the Freeman and Halversonpatent, if it is desired to be able to read the typed symbols, a.

pigment may be incorporated in each area so that the symbols can be readvisually.

While the preferred form of the present invention utilizes ateletypewriter without any change except for the-particular ribbon frameholder on the back of the typing head .or box, it

is, of course, possible to use modified typewriters, for example thosewhich'movable platens, which does not require moving the typing head orbox one unit to the right with each succeeding typing symbol. In suchacase it is possible to have a continuous ribbon which is clipped on theback of the typingbox or head with a sufficient slack for the movementof the box to align the particular type head which is chosen by theparticular key struck on the teletypewriter keyboard. When a particularpart of the ribbon has become worn, it may be advanced and a new areaclipped in proper alignment to the back of the typing box. However, itis so simple to replace the frames with pieces of ribbon that in mostcases it is preferred to utilize a teletypewriter machine which is nototherwise modified. In the preferred form where no modification of theteletypewriter is needed, this is an important advantage as, of course,the teletypewriter can be used for ordinary transmissions simply byunclipping the frame and replacing the normal teletypewriter ribbon.This is of advantage because it is not always necessary that allmessages be in the photoluminescent code.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic elevation,partly broken away, of a teletypewriter equipped with the presentinvention;

FIG. 2 is a section through the platen and type box or head;

FIG. 3 is a detailed isometric of the frame clipped on theteletypewriter typing box and showing a frame with ribbon just beforeinsertion; and

FIG. 4 is an elevation of the typing box with ribbon inserted, lookingfrom the back, as shown by the arrow 4-4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As the teletypewriter is notchanged except for the clip-on frame, only so much of the typewritermechanism is illustrated as is necessary to understand where theelements of the present invention are attached.

FIG. 1 shows, in diagrammatic fonn, an elevation of a typicalteletypewriter, for example a Model 28 unit of the Teletype Corporation,with keyboard and keys II. A portion of the typewriter is broken away sothat the platen 3 shows, a typing box or head 1 and the forward clips 6of the frame 7 carrying the typewriter ribbon 13 with the separate areas9 aligning with the typing box types. The insertion handle 8 is alsoapparent in FIG. 1.

It should be noted that the breaking away includes breaking away aportion of the typing box itself so that the ribbon can be seen. Thisalso breaks away the actuating hammer, which will be described inconnection with some of the other figures. The operation of theteletypewriter machine is the normal one. When a key is struck the box Iis aligned to bring a certain typeface corresponding to the keydepressed in alignment with the typing position on the platen 3. Theparticular typeface is then struck with the hammer I6, which does notappear on FIG. 1 but is shown in FIG. 2. When the next key is struck, asis normal in a teletypewriter, the box moves one space to the right.That is to say, the box as a whole moves because, of course, when thenext key is depressed this may be for a different symbol and so the boxwill have to be repositioned but the symbol appearing opposite a typingposition will be one position to the right. This is standardteletypewriter mechanism and is not changed by the present invention. Ashas been stated above, the ribbon frame fits in the holder with a smallamount of play. Slight movement of the impregnated ribbon areas resultsfrom the normal vibration of the machine during operation. FIG. 2 showsa section through the platen 3 with paper 4 and is also a sectionthrough the typing box, each of the typefaces 2 having an actuating rodwith a face 12 which is struck by the hammer 16 when it is in alignment.Normally the types are in a retracted position by reason of theindividual springs 17. This is, of course, standard teletypewriterdesign and this portion is not changed by the present invention.

FIG. 2 shows that a frame has been clipped with clips 6 onto the top ofthe type box. The frame, which is shown at 5, is provided with a slotthe two sides of which are of different cross section, a triangular oneat the right at 14 and a square one at the left at 15. The frame 5extends down to the bottom of the type box, as appears in FIG. 2.

The ribbon I3 is mounted in the frame 5 and is provided with a series ofseparated rectangular areas 9 which align accurately with the typefacesin the type box 1. The ribbon frame '7 has mating edges which are of thesame shape as in the channels 14 and 15 in the slot of frame 5. It isthus impossible to insert the ribbon frame 7 incorrectly. When inserted,the ribbon appears as shown in FIG. 4, and each of the areas 9 isimpregnated with a different coding ink, the coding componentscorresponding to the particular symbol on the type bars of the box I. Itwill be noted that there is a separation between the areas 9 andtherefore it is not possible for ink from one area to contaminate thatof the other. When the ribbon is inked, of course it is through asuitable mask which prevents any contamination at that time.

When the teletypewriter is used with the present invention and aparticular key is depressed, the type box 4 is moved so that thecorresponding type head is in printing position, and of course theportion 9 of the ribbon is in the same position. Then the hammer 16moves forward in the normal manner striking the head 12 of the rod onthe particular type face 2 and an impression of the symbol in theparticular coded ink results. The type box is then moved one space tothe right and when the next key is struck it aligns the correspondingtypeface one position to the right so that a line of typing is producedacross the paper 4. As in standard teletype operation, which is notchanged by the present invention, the platen is, of course, turned atthe end of a line and the type box 1 is returned to its left-handposition to start a new line. Depending on whether the areas 9 of theribbon have an additional pigment which is visible under visible light,the typed message will either be secret, because the coded inks arecolorless, or will appear also in a suitable color for visual reading.One type of message can be changed to the other simply by inserting theproper ribbon frame 7. Some of these frames will have ribbons which donot have an additional pigment in the areas 9 and some will not. Thepossibility of typing either entirely secret messages which can only bedeciphered under ultraviolet light illumination or those which are bothreadable visually and under ultraviolet illumination constitutes animportant practical additional flexibility of the present invention.

The invention has been described in a typical example with a standardteletypewriter only slightly modified to take the ribbon frame holder.Other models of teletypewriters can be suitably slightly modified in asimilar manner. It will be noted that the impregnated areas on theribbons are rectangles with slight separation between areas. Theparticular shape of the areas is not important. They can be rectangles,circles, or any other suitable shape so long as they assure thatmisalignment will not take place.

Iclaim'.

I. In a teletypewriter provided with keyboard and keys, a platen, atyping head movable to bring a predetermined typing head correspondingto the particular key depressed into printing position, and a hammer tocause this type head to move forward against the platen, themodification which comprises:

a. a removable holder attachable onto the type box of the teletypewriterand extending down the backface of said type box, the frame beingprovided with a slot and aligning edges; and

b. a separate frame carrying ribbon and mating with the aligning edgesof the slot in said holder, the frame carrying a ribbon with discreteareas each with its own particular ink corresponding to a particularsymbol, the ink having coding components of photoluminescentconstituents and each area having the proper code for the particularsymbol whereby when the ribbon frame is inserted, each area with itsdifferent coded ink is aligned with the corresponding typeface in theteletypewriter type box and typing results in the coded inkcorresponding to the particular symbol of the particular key struck.

2. A modified teletypewriter according to claim 1 in which theribbon-containing frame is provided with a tab or handle at the top.

3. A modified teletypewriter according to claim I in which the areas onthe ribbon in the different coded inks are v the inked areas on theribbon m the frame carry in addition to the coding components a pigmentwhich is visible under visi ble light illumination.

6. A modified teletypewriter according to claim 2 in which the inkedareas on the ribbon in the frame carry in addition to the codingcomponents a pigment which is visible under visible light illumination.

1. In a teletypewriter provided with keyboard and keys, a platen, atyping head movable to bring a predetermined typing head correspondingto the particular key depressed into printing position, and a hammer tocause this type head to move forward against the platen, themodification which comprises: a. a removable holder attachable onto thetype box of the teletypewriter and extending down the backface of saidtype box, the frame being provided with a slot and aligning edges; andb. a separate frame carrying ribbon and mating with the aligning edgesof the slot in said holder, the frame carrying a ribbon with discreteareas each with its own particular ink corresponding to a particularsymbol, the ink having coding components of photoluminescentconstituents and each area having the proper code for the particularsymbol whereby when the ribbon frame is inserted, each area with itsdifferent coded ink is aligned with the corresponding typeface in theteletypewriter type box and typing results in the coded inkcorresponding to the particular symbol of the particular key struck. 2.A modified teletypewriter according to claim 1 in which theribbon-containing frame is provided with a tab or handle at the top. 3.A modified teletypewriter according to claim 1 in which the areas on theribbon in the different coded inks are separated from each other withuninked zones so that contamination of one area having one coded inkwith that from another is impossible.
 4. A modified teletypewriteraccording to claim 2 in which the areas on the ribbon in the differentcoded inks are separated from each other with uninked zones so thatcontamination of one area having one coded ink with that from another isimpossible.
 5. A modified teletypewriter according to claim 1 in whichthe inked areas on the ribbon in the frame carry in addition to thecoding components a pigment which is visible under visible lightillumination.
 6. A modified teletypewriter according to claim 2 in whichthe inked areas on the ribbon in the frame carry in addition to thecoding components a pigment which is visible under visible lightillumination.